KR20020089994A - The equipment and method heat treatment gas - Google Patents

Abstract

PURPOSE: A method and an apparatus for nitriding heat treatment gas are provided to nitride a metallic substance prepared in a furnace by mixing ammonia gas with gas generated by heating alumina(Al) and nickel(Ni) catalyst in a retort container equipped with automatic control unit. CONSTITUTION: The apparatus for nitriding heat treatment gas comprises a furnace(10) which refractory bricks(11) are constructed on the outer surface, and an electric heating unit(12) installed on the inner wall; a retort(20) that is installed at one side of the furnace(10) and a container having a dimension of 350 ¥õ x 2000 L x 15 ton made of an inconel special metal; an injection nozzle(71) for ejecting the mixed gas into the furnace(10) through a gas pipe(70) after mixing a gas generated by mixing 50 wt.% of alumina(Al) solid catalyst with 50 wt.% of nickel(Ni) solid catalyst in the retort containing ammonia gas(20) at temperature of 1050 deg.C; an ammonia tank installed at one side of the retort containing ammonia gas(20) in a mixing ratio of 2:8; a basket(30) which is formed as a multilayer structure inside the furnace(10), and on which mechanical parts(32) to be nitriding heat treated are arranged; a hook(31) which is installed on the upper part of the basket(30) in such a manner that the hook(31) is hung up at the inner part of the furnace(10); an exhaust gas treatment unit(40) which is installed at the other side of the furnace(10) to treat exhaust gas inside the furnace(10); and an electric control box(50) for controlling temperature and heating units of the furnace(10).

Description

Gas nitriding heat treatment method and apparatus therefor {The equipment and method heat treatment gas}

The present invention relates to a metal heat treatment method using alumina and a nickel catalyst, a new chemical reaction gas generated by heating alumina (Al) and nickel (Ni) catalyst contained in a retort vessel in a gas automatic control device. The present invention relates to a gas-nitriding heat treatment and an apparatus invented to mix a gas and an ammonia gas so as to nitrate a metal material prepared in a furnace.

Conventionally, there have been various metal heat treatment methods, but this heat treatment method is a heating source having a bottom hole for carrying in and out of a treatment object / heating object to be disposed at a treatment position, as in the case of Patent Registration No. 221984, "Heat Treatment Method and Apparatus." A heat treatment method for heat-treating an object with a vertical process tube having an upper portion thereof, the process of passing an object to be processed into a mounting portion of an object holder to be brought in at a lower stop position and / or raising the object holder by The temperature measured by the process of preheating the workpiece by stopping the placing unit at the intermediate stop position from the lower stop position and the temperature sensor disposed on the back side of the workpiece to which the workpiece is being preheated is in a predetermined range. Is to move the workpiece upwards from the intermediate stop position and / or raise the workpiece holder again. Stopping the placing portion at an upper stop position in the process tube above the intermediate position and heat-treating the workpiece, and / or dropping the object holder after the end of the heat treatment to remove the workpiece from the placing portion at the lower stop position. A heat treatment method and / or an apparatus comprising a vertical process tube and / or a workpiece having a lower end hole for carrying in and out of the workpiece and having a heating source for heating the workpiece disposed at the processing position thereon. A workpiece holder having a mounting portion and carrying the workpiece on the mounting portion from the lower end of the process tube to the processing position and / or disposed on the surface side of the workpiece on the mounting portion and measuring the temperature on the surface side thereof. A second temperature sensor disposed on the rear surface side of the object to be processed on the placement unit and opposite to the first temperature sensor and measuring the temperature of the rear surface side; There has been a heat treatment apparatus having means for detecting the temperature of the workpiece based on the output of the degree sensor and / or the first and second temperature sensors, but such a heat treatment method and the apparatus require considerable heat generating energy and the heat treatment apparatus is complicated. There is considerable difficulty in handling,

In addition, the conventional gas nitriding heat treatment not only processes metals useful for gas nitriding but also takes 72 hours for heat treatment, so the enormous power consumption and environmental problem manufacturing time is too long, thus obtaining a metal heat treatment to be obtained in a limited time. There was a problem.

The present invention has been made in view of the above-mentioned problems, and the alumina (Al) and nickel (Ni) solid catalysts are mixed and embedded in a retorto made of an Inconel special metal container at 50:50, and then 1050. When heated to ℃, gas gas of chemical reaction generated from the mixed catalyst of retorto is blown into the upper gas pipe, and is first introduced into the temperature of 150 ℃ ~ 300 ℃, and then the ammonia gas 8 and Al at the internal temperature of 300 ℃ ~ 550 ℃. By mixing the secondary mixed gas at the proportion of + Ni mixed gas 2 (the difference in the mixing ratio occurs depending on the size of the furnace), the gas is blown through the blowing nozzle located at the bottom of the furnace into the basket containing the metal nitride heat treatment material. It is intended to be nitrided heat treatment. The present invention made as described above is to be able to heat-treat carbon steel, alloy steel, special steel and at the same time to reduce the heat treatment time to 1/10 of the existing and to save energy and industrial pollution of industrial power.

1 is a block diagram of a gas-nitriding heat treatment process according to the present invention.

2 is a schematic view of a gas-nitriding heat treatment apparatus according to the present invention.

Figure 3 is a cross-sectional configuration of the retorto in accordance with the present invention.

Figure 4 is an illustration of a basket according to the present invention.

<Description of Signs of Main Parts in Drawings>

10: Ro 11: Refractory brick

12, 12 ': Electric heating device 20: RETORT

21, 22: gas control valve 23: gas automatic control device

30: Basket 31: Hook

32: mechanical part 40; exhaust gas treatment device

50: electric control box 60: ammonia tank

70: gas piping 71: injection nozzle

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

A metal material sorting process for sorting into carbon steel, alloy steel, and special steel;

A heat treatment step of temper treatment at about 580 ° C. or higher to prevent deformation of the metal material during heat treatment;

A part processing step of cooling the tempered metal material and then precision processing and finishing the desired parts;

Inserting a machined part into a mesh basket for nitriding heat treatment, and charging the same into a furnace;

A heating step of mixing 25 kg of alumina (Al) solid catalyst and 25 kg of nickel (Ni) solid catalyst inside the retort and heating to 1050 ° C. to generate a mixed gas gas;

Firstly injecting Al + Ni gas gas generated in the retorto into a furnace having a temperature of 150 ° C. to 300 ° C .;

Mixing alumina heated by heat in the retort with nickel mixed gas 2 and ammonia (NH ₃ ) gas 8 to inject a secondary mixed gas into a furnace having a temperature of 300 ° C. to 550 ° C. to heat the metal nitride;

The heat treatment process is performed by removing the basket containing the heat-treated metal nitride product through a cooling process of quenching with a separate blower.

The heat treatment apparatus for performing the nitriding heat treatment process is as follows.

A furnace having a firebrick 11 formed on an outer surface thereof and an electrothermal heating device 12 installed on an inner wall thereof;

One side of the furnace 10 includes a retorto 20 of an Inconel special metal container having a size of 350Ø × 2000L × 15t;

In the retorto 20, alumina (Al) solid catalyst 50: nickel (Ni) solid catalyst 50 is mixed and heated to 1050 ° C. in a tank 60 provided with one side ammonia gas 8: Al + Ni. An injection nozzle 71 capable of mixing gas 2 and ejecting the gas into the furnace 10 through the gas pipe 70;

A basket 30 having a multi-layer structure inside the furnace 10 in which a mechanical part 32 which is a nitride heat treatment product is disposed;

A carrying hook 31 installed at the top of the basket 30 to be charged into the furnace 10;

The other side of the furnace 10 is a nitriding heat treatment apparatus including an exhaust gas treatment device 40 for processing exhaust gas inside the furnace, and an electric control box 50 provided to control the temperature and the heating device of the furnace.

Reference numerals 21 and 22 are ammonia gas control valves and Al + Ni gas control valves, 80 is a retorto gas automatic control device, and 90 is a thermometer displayed to check and control the furnace temperature.

Looking at the embodiment of the present invention configured as described above are as follows.

First, in order to process the product, metal materials are classified through a sorting process that is classified into carbon steel, alloy steel, special steel, and general steel.

After the sorting process of the metal material is subjected to a temper treatment process of about 580 ℃ or more depending on the metal properties in order to give a processing deformation and metal structure changes.

The tempered metal material is subjected to a mechanical part processing process of cooling and precision processing to desired parts after cooling to handle during processing.

Hoist or to load the machined parts in the furnace using the upper hook 31 on both sides of the basket 30 after placing the mechanical parts up and down in the multi-stage mesh-shaped basket 30 for heat treatment. The basket is transported by crane.

After charging the machined part 32 machined inside the furnace as described above, the alumina (Al) solid in the retorto 20 of the Inconel special metal container of 350Ø × 2000L × 15t size provided on one side Catalyst 50: A nickel (Ni) solid catalyst 50 was mixed and incorporated and then heated to 1050 캜.

The alumina (Al) solid catalyst and the nickel (Ni) solid catalyst embedded in the retorto 20 are supplied to the gas gas (Al + Ni) of the chemical reaction generated by heating through a spout at the top of the retorto. It is discharged through the gas pipe 70 connected with.

The gas gas (Al + Ni) discharged from the retorto is first injected at a furnace temperature of 150 ℃ to 300 ℃ and the temperature of the furnace rises to 300 ℃ ~ 550 ℃ when the mixture of Al + Ni gas gas 2 and ammonia (NH ₃ The gas gas mixed at a ratio of 8) is injected through the injection nozzle 71 inside the furnace 10 to the basket 30 in which the mechanical parts 32 are arranged as shown in FIG.

As described above, the alumina (Al) + nickel (Ni) + ammonia (NH ₃ ) mixed gas is sprayed while the temperature of the furnace is increased by about 300 ° C. using the electrothermal heating device 12 installed on the inner wall. The mechanical part 32 arranged in the heat treatment is nitrided.

The time and temperature at this time are as shown in the graph of gas and gas input curves of temperature and chemical components in Table 1 below.

As shown in the graph above, when the temperature in the furnace is increased, the gas generated from the Al + Ni catalyst up to 150 ° C. is introduced into a mechanical component, which is a metal heat treatment product, and the Al + Ni + NH ₃ gas is introduced from 300 ° C. to 550 ° C. At this time, after completion of the work at 530 ℃ -550 ℃, stop the power heating device, close all gas valves, inject nitrogen (N ₂ ) into the furnace containing the product for 30 minutes, and after completion, take out the parts and cool them with a quench blower. do. In the heat treatment, there is a difference between the mixture gas and the time control and the rising temperature according to each steel type of carbon steel, alloy steel, and special steel, but this can be overcome by the operation of the electric control box.

In addition, according to the size of the furnace, the number of nozzles installed at the inner bottom increases and decreases, so that the mixing ratio of alumina, nickel gas, and ammonia gas is changed. In other words, ammonia gas may be mixed at a ratio of alumina nickel catalyst gas 2, and ammonia gas 7: alumina and nickel catalyst gas 3, or ammonia gas 6: alumina and nickel catalyst gas 4 may be mixed. It is sent to the injection nozzle 71 of (10) to nitride the heat treatment of the mechanical component 32.

At this time, when mixing ammonia gas, alumina and nickel catalyst gas can be mixed using the ammonia gas control valve 21 and Al + Ni catalyst gas control valve 22 installed in the gas pipe (70), depending on the equipment By attaching a valve to set the setting value, the computer can control the mixing ratio.

Therefore, the time of gas nitridation heat treatment in the furnace 11 at 300 ° C. to 550 ° C. by the mixed gas of Al + Ni + NH ₃ in the furnace 11 is somewhat different depending on the material of the metal. Will be able to finish.

The temperature of the furnace during the gas nitrification heat treatment can be confirmed by a thermometer 90 installed at the top, the overall management of the gas nitrification heat treatment system is made by the control box 50, in the furnace 10 and retorto The heating of (20) makes it possible to heat the inside by an electrothermal heating device installed in a conventional manner on the inner wall.

The heat-treated parts are taken out in a state embedded in the basket 30 caught in the furnace 10 and rapidly cooled by a separate blower.

The rapidly cooled mechanical parts 32 are taken out of the basket 30 and finished with quality inspection daily, and then supplied to a parts assembly factory or a real user.

Briefly summarized the process sequence of the present invention carried out as described above, the metal material sorting process → the tempering treatment process to 580 ℃ or more → parts processing process → gas nitrification heat treatment process → rapid cooling process → product inspection process → product completion In the step of, a heat treatment step is performed.

The present invention is a gas gas 2 generated by mixing a special alumina (Al) solid catalyst (50%) and nickel (Ni) solid catalyst (50%): a gas gas consisting of ammonia gas (NH ₃ ) 8 (furnace capacity and metal material According to the gas heat-treatment method using the gas permeation force, it is possible to control the metal nitride heat treatment process using gas permeation force. In the present invention, the heat-treatment was performed at 8 to 16, so that the slow cooling was to be performed.

Thus, the present invention improves the mechanical properties of the heat-treated metal by using nickel catalyst gas and ammonia gas which improves the stiffness hardness of the metal while reducing the hardness of alumina and hardness, and can easily heat-treat carbon steel, alloy steel, and special steel. In addition, the heat treatment time of the metal heat treatment object can be shortened to reduce power energy and prevent environmental pollution. In particular, the heat treatment process can be automated to increase output and produce high quality products.

Claims (4)

A metal material sorting process for sorting into carbon steel, alloy steel, special steel, and general steel; Tempering to about 580 ° C. or more to prevent deformation of the metal material during heat treatment; A part processing step of cooling the tempered metal material and then precision processing and finishing the desired parts; Inserting a machined part into a mesh basket for nitriding heat treatment, and charging the same into a furnace; A heating step of mixing 25 kg of alumina (Al) solid catalyst and 25 kg of nickel (Ni) solid catalyst inside the retort and heating to 1050 ° C. to generate a mixed gas gas; Firstly injecting Al + Ni gas gas generated in the retorto into a furnace having a temperature of 150 ° C. to 300 ° C .; Mixing alumina heated by heat in the retort with nickel mixed gas 2 and ammonia (NH ₃ ) gas 8 to inject a secondary mixed gas into a furnace having a temperature of 300 ° C. to 550 ° C. to heat the metal nitride; A gas-nitriding heat treatment method characterized in that the heat treatment process is performed by removing the basket containing the heat-treated metal nitride product through a cooling step of quenching with a separate blower. A furnace having a firebrick 11 formed on an outer surface thereof and an electrothermal heating device 12 installed on an inner wall thereof; One side of the furnace 10 includes a retorto 20 of an Inconel special metal container having a size of 350Ø × 2000L × 15t; In the retorto 20, alumina (Al) solid catalyst 50: nickel (Ni) solid catalyst 50 is mixed and heated to 1050 ° C., and the gas generated at one side of the tank 60 with ammonia gas is 2: 8. An injection nozzle (71) capable of mixing and spraying the furnace (10) through the gas pipe (70); A basket 30 having a multi-layer structure inside the furnace 10 in which a mechanical part 32 which is a nitride heat treatment product is disposed; A hook 31 installed on the top of the basket 30 so as to span the inside of the furnace 10; On the other side of the furnace 10, the gas-nitriding heat treatment, characterized in that the exhaust gas treatment device 40 for processing the exhaust gas in the furnace and the electric control box 50 provided to control the furnace temperature, heating device Device. The method of claim 2, A basket (30) charged in the furnace (10) is formed in a multi-layered structure and the partition is made of a mesh body is characterized in that the gas nitriding heat treatment apparatus is made to smoothly contact with Al + Ni + NH ₃ gas. The method of claim 2, The gaseous gas and ammonia (NH ₃ ) gas generated by heating the alumina (Al) catalyst gas and the nickel (Ni) catalyst gas in the retorto 20 to 1050 ° C. are selectively mixed, and the Gas-nitriding heat treatment apparatus, characterized in that to be injected into.